The invention relates to a rotary angle encoder for monitor pedal value transducers and clutch actuators for vehicular applications.
In a known pedal value transducer (German Patent Application DE 34 11 393 A1), a rotary angle sensor is provided for detecting the swiveled position of the pedal coupled to it; it cooperates with a pedal-actuated transducer shaft rotatably supported in a housing. A wiper ring potentiometer that furnishes an electrical rotary angle signal corresponding to the pedal position is provided as the rotary angle sensor.
Although current demands can for the most part be met by such pedal value transducers that use potentiometer sensors to detect the rotary angle, nevertheless the low reliability of potentiometers is disadvantageous for certain control tasks.
As robust and economical travel transducers to meet accuracy demands that are usual for large-scale mass production, plunger armature transducers have long been known, that is, coils with a core or armature displaceable in them in accordance with the travel to be detected, and are used in the motor vehicle field, for instance in controlling headlight beam angles.
The variation in inductivity of a coil is evaluated by the inward movement of a plunger of a ferromagnetic core. To linearize such a characteristic curve of such a sensor, a plurality of series-connected coil chambers with a different number of turns is used.
Other contactless sensors operating on magnetoresistive or inductive principles have high sensitivity to many interference variables and little deviation in the useful signal. Compensatory designs to overcome these disadvantages involve great major effort and expense, so that such sensors are not suitable for large-scale mass production.